Rear Main Seal Hell

[TimT]

Stoddard makes "speedy sleeves" for shafts that have grooves worn in them, odd the the od is that out of tolerance

[Porsche_monkey]

Tim T:

I think this is a magnesium case issue, from what I've read/surmised this is the result of the case twisting and distorting, over the last 30 years, on an engine that was marginal to begin with.

I'm sort of hoping Wayne or someone with case machining expertise will chime in, but I suspect that the bore in this area is usually cleaned up when the cases are sent for align boring.

Of course this leads to the question: If this is normally done how do they sleeve it back to 85 mm?

[Wayne 962]

This is a problem that should be cleaned up when the case is machined - I'll have to think on it and ask some machinists what they think...

-Wayne

[Porsche_monkey]

Here are the do-it-yourself instructions for this repair.

1. Load the engine onto your horizontal boring mill. Be sure to square and level the crank. Dial indicate the crank to find the center.




Bore out to 86.00 mm, using your precision boring bar.




Simply press in your sleeve (with loctite), which of course is 85.00 ID with 0.5 mm thick walls. Follow on with your standard seal and Curil-T.



Note the little notched area where the sleeve nad the red loctite are visible.

Cross your fingers and drive off.

[Ho Hum 74]

Hopefully that stops the dripping. Let us know how it worked out.

T

[Fishcop]

Man, I hope I don't have this problem!

[Ho Hum 74]

You and me mate. Speaking of which, where is yours? You've been going at it for a while now. What's holding you up?

Tristan

[Fishcop]

I've kinda held myself up by not getting orders right in respect of lead in times. I got back my left camshaft last night (wasn't happy with one of the lobes after having their profiles changed from CIS to S). I'm still waiting for a camshaft holder tool to time my engine so I can check piston to valve clearance. I'll then be pulling it all down and rebuilding it with gaskets/sealant. Having the 2.0 still in the car means I've always got wheels, so I'm not rushing anything

I'm living perpetual paranoia that my engine will leak after reading all these bad news threads....

[Jay Auskin]

PBH--that has to win the award for the most intense setup of fixing a fully assembled engine I've ever seen...or even thought I'd see. I hope your problem is fixed. That effort truly deserves a leak free engine.

I'll have my engine out tomorrow. We'll see what mine looks like.

[Porsche_monkey]

Originally posted by Jay Auskalnis
PBH--that has to win the award for the most intense setup of fixing a fully assembled engine I've ever seen...or even thought I'd see.

I'm not sure whether I should be proud or ashamed.

I guess it's proud if it works...

[Ho Hum 74]

I'm living perpetual paranoia that my engine will leak after reading all these bad news threads....

John,

I think that there's a good chance something will leak. Don't freak out, it's just probable. My engine developed such high oil pressures that it just finds many places to seep out of. I put in the cam oil restrictors which hold the pressure at 20 PSI for every 1k.

Places where I had oil leaks of varying amounts:

1. Some of the delicate oil lines feeding the tensioners (didn't want to tighten too much)
2. Oil pressure switch (replaced a couple of times)
3. Crank-case breather hose
4. Thermostat
5. Flywheel seal
6. Intermediate shaft cover

I can live with some seepage (normal?) but being black flagged for oil dropping on your heat exchangers from the pressure switch and smoking is not fun. Especially since all you want to do is drive.

Oh well, live and learn.

Tristan

[Porsche_monkey]

When I finished my engine I thought 'this will never leak, if it does, I'll fix it'. Now, a small drop here or there doesn't seem so bad...

I think your perspective changes based on the seriousness of the leaks you've fixed and the time you've spent. At some point you need to get on with your life (and drive your car).

See this link (look at the pics), and think about some of the oily Porsche engines you've seen with happy content drivers...

Head leaks

[Ho Hum 74]

PBH is EXACTLY on the money. That's just how I feel.

Hey, my BMW friends tease me because of my recent dump of oil at a BMW DE. The tech sheet says, “No oil leaks (some seepage is normal)”. Now they always joke about some seepage being "normal".

I just smile, they don't understand what it's like to drive this baby on the track.

T

[Fishcop]

I know what you're saying, but I can't help but remember me mocking English motorcycles and their owners Here I am 10 years later being mocked for my oily machine...

My current engine in the car drops about a quarter sized pool from both sides of the engine each week. Guess I can live with it...

[Jay Auskin]

Fishcop--just take your time with seals, etc. I pulled my engine tonite, and found my problem. I installed my main crankshaft seal (flywheel end) like a moron. When I installed the other case half, the seal was cocked, and it didn't dawn on me just how crooked this seal was.

There's a slight wetness near the pulley end too. I'm going to look into that, and see. if I can seal things up a bit better. But if it's my nose bearing, well...I guess I'll cope. At least this won't drip on any heat exchangers.

[AndreasLanghoff]

There is an article by Gregory Brown in the Porsche owners club magazine winter 2002. The leaking on the flywheel seal could also be related to using not original main bearings. On the original main bearings the 2 notches are going towards zero depth at the outer end of the flange. This is to reduce oilpressure on the seal.

Andreas

[Porsche_monkey]

Originally posted by AndreasLanghoff
There is an article by Gregory Brown in the Porsche owners club magazine winter 2002. The leaking on the flywheel seal could also be related to using not original main bearings. On the original main bearings the 2 notches are going towards zero depth at the outer end of the flange. This is to reduce oilpressure on the seal.

Andreas

I believe I have original bearings, so while I'll lie awake at night hoping this is so, I am pretty sure my problem was ovality. I would also expect that additional pressure on a lip seal would help seal the shaft, but leak on the case.

Anyhow, I think mine is fixed. So far no drippage.

Case closed, no pun intended.

[Porsche_monkey]

Originally posted by Wayne at Pelican Parts
This is a problem that should be cleaned up when the case is machined - I'll have to think on it and ask some machinists what they think...

-Wayne

Any further thoughts Wayne? Just wondering for next time. The more I think about this the more bizarre it seems.

[Ho Hum 74]

PBH,

Is your motor dry now? Hope so.

Tristan

[Porsche_monkey]

Hey it's a Porsche. Lets just say that area of the engine is dry now.

I had an ongoing unrelated problem with my transmission puking oil out the overflow hole in the top. This would run down the case onto the output shafts and throw oil everywhere. I guess I overfilled the tranny.

Anyhow I connected a 1/4" nylon tube from the overflow outlet to the transmission mount crossmember and the last little bits of overflow just drip onto the ground now.

Everything else looks (and runs) fine.